The present invention relates to silent-discharge-assisted glow discharge excitation gas laser devices. More particularly, the invention relates to a gas circulation type silent-discharge-assisted glow discharge excitation gas laser device in which preliminary ionization caused by a silent discharge in the flow of laser gas defines operating conditions to obtain a large power density glow discharge of uniform quality.
A high speed gas circulation type high output CO.sub.2 laser is disclosed by W. B. Tiffany, R. Targ and J. D. Foster, Appl. Phys. Letters 15, 91 (1969). In the laser structure therein described, a direction of gas flow, a discharge direction for the gas, and the optical axis are mutually orthogonal. This makes the overall size of a device unavoidably quite large.
A further device is described by E. Hoag, H. Pease, J. Staal, and J. Zar, Appl. Optics 13, 1959 (1974). In this laser device, a large discharge volume is required to provide continuous oscillation at a high output level. Further, an electron beam is required for an auxiliary ionizing source. As in the previously discussed case, the overall size of the device is unavoidably large.
Accordingly, it is an object of the present invention to provide a laser device of the above discussed type, but which is significantly reduced in size.
It is a further object of the invention to provide such a laser device having a high output.